1. Field of the Invention
The present invention relates to a fat or oil composition in powdery or granular form and a process for producing the same. More particularly, the present invention is concerned with a composition comprising a fat or oil, a base material having the fat or oil included therein by occlusion or absorption and a polyol having at least two hydroxyl groups, which composition is in the form of a powder or granules having a water content, a maximum particle diameter, an average particle diameter and an angle of repose in specific ranges. The fat or oil composition of the present invention has its fat or oil component well included therein by occlusion or absorption irrespective of whether the fat or oil component is liquid, semisolid or solid and has excellent handling characteristics because it has a good flowability. The composition is also advantageous in that when it is contacted with water, the fat or oil is quickly separated without forming an unfavorable emulsion with water, leading to great benefits in use for various food products. The present invention is also concerned with a simple and economical process for producing the above-mentioned fat or oil composition.
2. Discussion of Related Art
Powdery fat and oil products are widely used in various instant foods such as premixes for bread, cakes, cookies, doughnuts, pancakes, ice cream and the like.
Powdery fat and oil products have conventionally been produced by one of the following methods.
(1) A freeze-pulverizing method in which a solid fat or oil having a high melting point is pulverized at a low temperature to obtain a powder.
(2) A spray-cooling method in which a melted edible oil is sprayed into a chamber maintained at a low temperature (about 15 .degree. C.) to freeze the oil (see, for example, Japanese Patent Application Laid-Open Specification No. 54-126207).
(3) An absorption method in which a fat or oil is absorbed by an oleophilic material such as processed starch or cellulose.
(4) A spray-drying method in which an oil-in-water type emulsion that has been prepared using a synthetic emulsifying agent such as a sugar ester, a protein such as casein or gelatin, a starch, or the like, is spray-dried (see, for example, Japanese Patent Application Laid-Open Specification No. 55-150845).
The above-mentioned methods, however, have the following problems.
In method (1), only a hardened oil having a melting point of 60 .degree. C. or higher can be used as a starting material. For this reason, the powdery fat or oil product obtained by this method does not melt even upon eating and, therefore, cannot suitably be used in premixes such as cake mixes.
In method (2), only a solid fat or oil can be used as a starting material. Further, the powdery fat or oil product obtained by this method does not contain any substance for immobilizing a fat or oil and, therefore, is required to be refrigerated during storage and transportation.
With respect to method (3), if the fat or oil content of the powdery product obtained is high, not only the fat or oil is likely to exude from the powdery product, but also the flowability of the powdery product is decreased. Therefore, the fat or oil content of the powdery product is required to be low.
In method (4), the emulsion to be spray-dried is required to have a water content as high as about 70 to 90% in order to keep the viscosity of the emulsion at a level suitable for spray drying. For this reason, the amount of water to be evaporated is very large, leading to extremely high energy costs. Further, the powdery fat or oil product obtained by this method forms an emulsion with water and, therefore, has only limited use.
It is conceivable to use powdery fat and oil products not only in premixes for pastry and ice cream as mentioned above but also in powdery soup mixes for instant noodle soup and in other type soup mixes, powdery roux mixes and powdery or granulated mixes for seasonings having high oil contents, such as condiments for use in Chinese food, salad dressings and mayonnaise. However, none of the powdery fat and oil products produced by the above-mentioned conventional methods can suitably be used in these soup mixes and seasoning mixes for the following reasons. Premixes containing a seasoning oil, such as premixes for instant noodle soup, Chinese soup and salad dressing are desired to have properties such that when water is added to the premix in order to prepare the soup or dressing, the oil component of the soup or dressing rapidly separates out and floats on the surface of the soup or dressing so as to enhance the flavor of the seasoning oil. As mentioned above, the powdery fat or oil product obtained by method (4) (spray-drying method) is likely to form a white emulsified, turbid mixture when the product is contacted with water. Therefore, if this product is used in premixes for soup or dressing containing a seasoning oil, when a soup or dressing is prepared from the premix, the oil component will not separate out and, therefore, will not fully exhibit the flavor thereof. Further, in methods (3) and (4), which may be applied to liquid oils and semisolid fats, special materials such as processed starch, cellulose, casein, gelatin and soybean protein are necessarily used as a component of the powder. Therefore, the use of the powdery fat or oil product obtained by method (3) or (4) in premixes for cakes, soup, seasonings and the like, is very likely to adversely affect the taste, flavor, texture and other eating characteristics of the food prepared from the premix.
For these reasons, the premixes now available for soup and condiments containing a fat or oil are limited to the following types.
(1) A premix in which a fat or oil component is independently packaged in a liquid or semisolid state. The other ingredients are separately packaged in powdery state.
(2) A premix in which a fat or oil component is packaged together with the other ingredients. The whole premix is in the state of a liquid or a paste.
(3) A powdery premix in which a fat or oil component has been absorbed by the other ingredients in a powdery state.
Premixes of types (1) and (2) are disadvantageous from the viewpoint of ease of handling of the premix in packaging and cooking processes. A premix of type (3) is also disadvantageous in that the amount of fat or oil which can be contained in the premix is required to be extremely small in order to avoid exudation of the fat or oil from the premix. immobilized ar temperatures above their normal melting point, leading to improvements in heat resistance of chocolate, prevention of separation of peanut oil from peanut butter and the like. However, a fat or oil composition in the form of a powder or granules is not described.
Japanese Patent Application Publication No. 61-13774 discloses a powdery fat or oil composition comprising an edible fat or oil having a melting point of 35 .degree. C. or lower, an enzymatically decomposed starch, a glycerine ester of a saturated aliphatic acid and/or a sorbitan ester of an unsaturated aliphatic acid. When water is added to this composition to obtain a mixture, oil drops are formed on the surface of the aqueous phase of the mixture but the aqueous phase becomes turbid. Further, unless the enzymatically decomposed starch to be used in this composition has an extremely large surface area, a desired powdery composition cannot be obtained.